A temperature control method for injection mold of automobile spare parts production

Abstract

The present application relates to the technical field of temperature control, in particular to a temperature control method for injection mold of automobile spare parts production, comprising: according to the difference between the temperature value of the cavity and the core and the required temperature value at the current time, respectively completing the first temperature adjustment of the cavity and the core, after the first temperature adjustment of the cavity and the core, obtaining the temperature value of each monitoring point in the cavity and the core at the next time of the current time, and the flow rate of the cooling liquid in the cooling system of the cavity and the core, so as to determine the local temperature difference consistency of the temperature zone of the cavity and the core, and respectively complete the second temperature adjustment of the cavity and the core. The present application can improve the precision of injection mold temperature control, and is beneficial to the high-precision production of high-precision automobile spare parts.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of temperature control, and in particular to a temperature control method for an injection mold for automobile parts production. BACKGROUND

[0002] Injection mold temperature control plays a crucial role in automobile parts production. With the continuous development of the automobile manufacturing industry, the requirements for parts are becoming higher and higher, especially in terms of precision, strength, and appearance quality. Injection molding process, as a common production method, has the advantages of high efficiency, low cost, and the ability to manufacture complex shapes. However, the control of injection mold temperature directly affects the quality and production efficiency of the final product, especially in the production of high-precision and high-performance automobile parts. Therefore, researching and developing more efficient and intelligent mold temperature control methods is a crucial link in future automobile parts production.

[0003] Existing problems: traditional mold temperature control usually cools and heats the entire mold as a whole, which involves more cooling and only uses the temperature control of the cooling liquid to adjust the mold cooling. Automobile parts production has high precision requirements, such as complex deep cavity parts, which have different cooling rates at different positions. Therefore, a temperature zone cannot meet the actual needs. In addition, during the cooling process in the temperature zone, there are often local temperature differences, and different sources of local temperature differences require different control strategies. The conventional partition temperature control method has poor effect on solving local temperature differences. SUMMARY

[0004] The present application provides an injection mold temperature control method for automobile parts production to solve the existing problems.

[0005] The injection mold temperature control method for automobile parts production of the present application adopts the following technical solutions:

[0006] An embodiment of the present application provides an injection mold temperature control method for automobile parts production, which includes the following steps:

[0007] Obtain the temperature value and required temperature value of the mold cavity and mold core at the current time; determine the probability of mold cavity and mold core water temperature adjustment according to the difference between the temperature value and required temperature value of the mold cavity and mold core at the current time; complete the first temperature adjustment of the mold cavity and mold core according to the size of the probability of mold cavity and mold core water temperature adjustment;

[0008] After the first temperature adjustment of the cavity and the core, the temperature values of each monitoring point in the cavity and the core at the next moment are obtained, and the flow rate of the cooling liquid in the cooling system of the cavity and the core is obtained; the local temperature difference consistency of the temperature zone of the cavity and the core is determined according to the distance and the temperature value difference of the monitoring points between the cavity and the core at the next moment of the current moment.

[0009] According to the local temperature difference consistency of the temperature zone of the cavity and the core, the temperature value difference between the monitoring points in the cavity and the core at the next moment of the current moment, and the flow rate of the cooling liquid in the cooling system of the cavity and the core, the second temperature adjustment of the cavity and the core is completed respectively.

[0010] Further, the specific steps of determining the probability of water temperature adjustment of the cavity and the core include the following:

[0011] At the current moment, the absolute value of the difference between the required temperature values of the cavity and the core is obtained, which is denoted as the theoretical temperature difference of the cavity and the core; the absolute value of the difference between the temperature values of the cavity and the core is obtained, which is denoted as the actual temperature difference of the cavity and the core; the temperature adjustment rate requirement value is determined according to the actual temperature difference of the cavity and the core and the theoretical temperature difference of the cavity and the core; the absolute value of the difference between the required temperature value and the temperature value of the cavity is obtained, which is denoted as the temperature deviation value of the cavity; the absolute value of the difference between the required temperature value and the temperature value of the core is obtained, which is denoted as the temperature deviation value of the core; the probability of water temperature adjustment of the cavity and the core is determined according to the temperature adjustment rate requirement value and the temperature deviation value of the cavity and the temperature deviation value of the core, respectively.

[0012] Further, the specific steps of determining the temperature adjustment rate requirement value include the following:

[0013] The normalized value of the absolute value of the difference between the actual temperature difference of the cavity and the core and the theoretical temperature difference of the cavity and the core is obtained, which is denoted as the temperature adjustment rate requirement value.

[0014] Further, the specific steps of determining the probability of water temperature adjustment of the cavity and the core according to the temperature adjustment rate requirement value and the temperature deviation value of the cavity and the temperature deviation value of the core include the following:

[0015] The normalized value of the product of the inverse proportion value of the temperature adjustment rate requirement value and the temperature deviation value of the cavity is obtained, which is denoted as the cavity water temperature adjustment probability; the normalized value of the product of the inverse proportion value of the temperature adjustment rate requirement value and the temperature deviation value of the core is obtained, which is denoted as the core water temperature adjustment probability.

[0016] Further, the specific steps of completing the first temperature adjustment of the cavity and the core according to the probability of water temperature adjustment of the cavity and the core include the following:

[0017] If the cavity water temperature regulation probability is greater than the preset regulation threshold at the current time, the fuzzy control algorithm is used to regulate the cooling liquid temperature in the cavity cooling system, and if the cavity water temperature regulation probability is less than or equal to the preset regulation threshold, the fuzzy control algorithm is used to regulate the cooling liquid flow rate in the cavity cooling system, thereby completing the first temperature regulation of the cavity.

[0018] According to the manner of completing the first temperature regulation of the cavity, the first temperature regulation of the core is completed according to the size of the core water temperature regulation probability.

[0019] Further, the specific steps of determining the temperature zone local temperature difference consistency of the cavity and the core include the following steps:

[0020] At the next time of the current time, the mean value of the temperature values of all monitoring points in the cavity is obtained, denoted as a first mean value, the normalized value of the absolute value of the difference between the temperature value of each monitoring point and the first mean value is obtained, denoted as the temperature value anomaly probability of each monitoring point, and the monitoring points with a temperature value anomaly probability greater than a preset temperature anomaly threshold are all recorded as abnormal monitoring points.

[0021] According to the distribution of the abnormal monitoring points in the cavity at the next time of the current time, the local temperature difference monitoring points in the cavity at the next time of the current time are selected from the abnormal monitoring points.

[0022] According to the manner of obtaining the local temperature difference monitoring points in the cavity at the next time of the current time, the local temperature difference monitoring points in the core at the next time of the current time are obtained.

[0023] According to the distance and temperature value anomaly probability difference between the local temperature difference monitoring points between the cavity and the core at the next time of the current time, the temperature zone local temperature difference consistency of the cavity and the core is determined.

[0024] Further, the specific steps of selecting the local temperature difference monitoring points in the cavity at the next time of the current time from the abnormal monitoring points include the following steps:

[0025] A preset number threshold N is used to obtain the shortest path length between any two abnormal monitoring points in the cavity at the next time of the current time using the Dijkstra algorithm, and the sum value of the shortest path length between each abnormal monitoring point and all other abnormal monitoring points in the cavity is obtained, denoted as the dispersion of each abnormal monitoring point. The first N abnormal monitoring points with the smallest dispersion are all recorded as the local temperature difference monitoring points in the cavity at the next time of the current time.

[0026] Further, the specific steps of determining the temperature zone local temperature difference consistency of the cavity and the core according to the distance and temperature value anomaly probability difference between the local temperature difference monitoring points between the cavity and the core at the next time of the current time include the following steps:

[0027] In the next moment of the current moment, from all local temperature difference monitoring points in the mold cavity, the local temperature difference monitoring point in the mold cavity closest to each local temperature difference monitoring point in the core is obtained, which is recorded as a matching mold cavity monitoring point, the inverse proportional normalized value of the distance between each local temperature difference monitoring point in the core and the matching mold cavity monitoring point is obtained, which is recorded as position consistency, the inverse proportional normalized value of the absolute value of the difference of the temperature value anomaly probability between each local temperature difference monitoring point in the core and the matching mold cavity monitoring point is obtained, which is recorded as temperature difference consistency, the mean value of the position consistency and the temperature difference consistency is recorded as the local temperature difference consistency relationship of each local temperature difference monitoring point in the core, and the mean value of the local temperature difference consistency relationships of all local temperature difference monitoring points in the core is recorded as the temperature zone local temperature difference consistency of the mold cavity and the core.

[0028] Further, according to the temperature zone local temperature difference consistency of the mold cavity and the core, the temperature value difference between the monitoring points in the mold cavity and the core in the next moment of the current moment, and the cooling liquid flow rate in the mold cavity cooling system, the second temperature adjustment of the mold cavity and the core is respectively completed, including the following specific steps:

[0029] In the next moment of the current moment, for all monitoring points in the mold cavity, the monitoring points with a temperature value anomaly probability less than or equal to a preset temperature anomaly threshold are recorded as normal monitoring points in the mold cavity in the next moment of the current moment.

[0030] When the temperature zone local temperature difference consistency of the mold cavity and the core is greater than a preset classification threshold, the mean value of the temperature values of all abnormal monitoring points in the mold cavity is recorded as a second mean value, the mean value of the temperature values of all normal monitoring points in the mold cavity is recorded as a third mean value, and the absolute value of the difference between the second mean value and the third mean value is recorded as the mold cavity local temperature difference size.

[0031] According to the mold cavity local temperature difference size and the cooling liquid flow rate in the mold cavity cooling system, the second temperature adjustment of the mold cavity is completed.

[0032] In the manner of completing the second temperature adjustment of the mold cavity, the second temperature adjustment of the core is completed.

[0033] Further, according to the mold cavity local temperature difference size and the cooling liquid flow rate in the mold cavity cooling system, the second temperature adjustment of the mold cavity is completed, including the following specific steps:

[0034] According to the principle of fuzzy control, the initial adjustment amount of the water flow rate is determined according to the mold cavity local temperature difference size.

[0035] The difference between the preset limited flow rate and the cooling liquid flow rate in the mold cavity cooling system is obtained When the difference is greater than 0, the difference is When the difference is greater than 0, the difference is inverse proportional normalized value of the difference, denoted as when the difference is less than or equal to 0, a preset constant is denoted as

[0036] a product of the degree of the current water flow rate approaching the limited flow rate and the initial adjustment amount of the water flow rate is obtained, denoted as a correction amount of the water flow rate adjustment amount;

[0037] a sum of the correction amount of the water flow rate adjustment amount and the initial adjustment amount of the water flow rate is denoted as a final adjustment amount of the water flow rate;

[0038] the cooling liquid flow rate in the cavity cooling system at the next time point after the current time point is regulated according to the final adjustment amount of the water flow rate, and the second temperature regulation of the cavity is completed.

[0039] The technical scheme of the present application has the following beneficial effects:

[0040] In the embodiment of the present application, the first temperature regulation of the cavity and the core is respectively completed according to the difference between the temperature values of the cavity and the core at the current time point and the required temperature values, so that in the temperature control of the injection mold for automobile parts production, the temperature control precision is improved by first performing the independent control of the temperature zones of the cavity and the core to meet the precise temperature control of complex deep cavity parts. After the first temperature regulation of the cavity and the core, the temperature values of each monitoring point in the cavity and the core at the next time point after the current time point and the cooling liquid flow rate in the cooling system of the cavity and the core are obtained, so as to determine the local temperature difference consistency of the temperature zones of the cavity and the core, and to respectively complete the second temperature regulation of the cavity and the core. Thus, in the temperature zone control, the local temperature difference is identified, and the type of the local temperature difference is identified by using the consistent relationship between the position performance and the specific temperature difference performance of the cavity and the core when the local temperature difference occurs, so as to effectively improve the accuracy of the obtained temperature difference type, and to respectively perform temperature regulation on different types of local temperature difference, thereby further improving the precision of the mold temperature control. Therefore, the present application can improve the precision of the temperature control of the injection mold, and is beneficial to the high-precision production of high-precision automobile parts. BRIEF DESCRIPTION OF DRAWINGS

[0041] In order to more clearly illustrate the technical scheme in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creating any creative labor.

[0042] Figure 1 The flow chart of the steps of the injection mold temperature control method for automobile parts production of the present application;

[0043] Figure 2 A schematic diagram of an injection mold for automobile parts production. DETAILED DESCRIPTION

[0044] In order to further illustrate the technical means and effects taken by the present application to achieve the predetermined object, the following describes in detail the specific implementation, structure, features and effects of a temperature control method for an injection mold for automobile parts production according to the present application, in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, the specific features, structures or characteristics in one or more embodiments can be combined in any suitable form.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0046] The specific scheme of the temperature control method for the injection mold for automobile parts production provided by the present application is described in detail below in combination with the accompanying drawings.

[0047] Please refer to Figure 1 , which shows a step flowchart of a temperature control method for an injection mold for automobile parts production provided by one embodiment of the present application. The method includes the following steps:

[0048] Step S001: Obtain the temperature values and required temperature values of the mold cavity and the mold core at the current time; determine the probability of water temperature adjustment of the mold cavity and the mold core according to the difference between the temperature values and the required temperature values of the mold cavity and the mold core at the current time; and complete the first temperature adjustment of the mold cavity and the mold core according to the size of the probability of water temperature adjustment of the mold cavity and the mold core.

[0049] In this embodiment, data acquisition is performed first. In the temperature control of the automobile parts injection mold, temperature data acquisition is the front-end sensing core of closed-loop temperature control, which needs to pass through accurate selection of sensors, scientific installation and efficient data acquisition to ensure the authenticity, real-time and uniformity of the temperature data of the core and the cavity, and to provide reliable basis for subsequent partition adjustment and dynamic phased control. Specifically, (1) core sensor: the mold temperature acquisition is mainly based on the contact type sensor, which is directly attached to the mold with accurate data. In this embodiment, K-type thermocouple is used, with a temperature range of 0 to 300 degrees Celsius, covering the mold temperature interval of commonly used injection materials for automobiles, avoiding data overflow due to insufficient range, with a precision level of Class 1, meeting the IEC 60584 standard, meeting the size of automobile parts, and the response time is less than or equal to 1 second, which can quickly capture temperature fluctuations and avoid lagging to cause defects. The probe structure is a metal sheath type, made of 316 stainless steel, resistant to oil stains and cooling liquid corrosion, and resistant to vibration. The protection level is IP67 for the probe part to prevent cooling water leakage and oil stains from entering the sensor, causing short circuit or precision decline. The sampling frequency is one per second, which meets the rapid fluctuations of mold temperature. (2) Sensor installation method: first, drilling, that is, drilling blind holes on the cavity side wall or bottom (non-part appearance surface), with a hole diameter of 0.1 to 0.2 mm larger than the probe diameter, and a hole depth ensuring that the top of the probe is 1 to 2 mm away from the cavity surface. Then drill an axial blind hole according to the core structure, with a hole depth of 5 to 10 mm shallower than the core depth, and a hole diameter of 0.1 mm larger than the probe. Record all the coordinates of the drilled holes, that is, the coordinates of the monitoring points. Then fix the sensor probe by inserting it into the blind hole and filling high-temperature conductive glue in the gap to ensure that the probe is in close contact with the hole wall. Finally, the wiring is done, that is, the sensor leads are drawn out from the wiring groove on the side of the mold, which needs to be reserved during mold design. The groove is 3 to 5 mm wide, and the lead is covered with a metal bellows. Finally, it is connected to the data acquisition module. (3) Data acquisition method: the sensor collects real-time temperature data and uploads it to the data processing center. Then the data processing center connects the temperature control platform of the injection molding machine and can directly read the cooling system parameters in the temperature control system of the injection molding machine, including the temperature and flow rate of the cooling liquid. It should be noted that the cavity and core in the mold are two independent temperature zones, and the cooling systems of the two temperature zones are independent of each other. Thus, the original data is collected and uploaded to the data processing center for subsequent data analysis for mold temperature regulation.

[0050] Preferably, in one embodiment of the present application, the method for completing the first temperature regulation of the cavity and the core respectively comprises:

[0051] Thus, the temperature value of each monitoring point in the cavity at each moment and the temperature value of each monitoring point in the core at each moment can be obtained, wherein there are multiple monitoring points (hole positions) in the cavity and multiple monitoring points (hole positions) in the core.

[0052] The mean value of the temperature values of all monitoring points in the cavity at each moment is taken as the temperature value of the cavity at each moment.

[0053] The mean value of the temperature values of all monitoring points in the core at each moment is taken as the temperature value of the core at each moment.

[0054] It is to be noted that: further, water temperature adjustment is performed based on the overall internal and external temperature difference. Due to the different heat distribution and functions of different regions of the mold and the high process requirements of automobile parts, different temperature control is required, such as deep cavity type automobile parts, the mold of which includes two parts of the cavity and the core, and the cooling essence is the process of heat transfer from the inside of the plastic part to the mold (core and cavity), and then exported through the mold temperature control system. In the core and cavity partition temperature control, the temperature relationship of the two is a direct mirror reflection of the cooling process of the injection molded part, that is, the core temperature corresponds to the cooling state of the inner surface of the plastic part, and the cavity temperature corresponds to the cooling state of the outer surface of the plastic part, and the temperature difference and synchronization of the two directly determines the solidification rate, thermal stress distribution and final molding quality of the inner and outer layers of the plastic part. Therefore, during the cooling process of the injection molded part, the temperature of the core and the cavity has its own demand, at this time, temperature adjustment is needed according to the actual temperature demand of the core and the cavity. The temperature adjustment of the cavity and the core mainly makes the actual temperature of the cavity and the core meet the temperature demand, and generally the cavity and the core have different temperature difference theoretical values in different cooling stages, that is, the temperature difference theoretical value of the cavity and the core, at this time, the greater the difference between the actual temperature difference of the cavity and the core and the temperature difference theoretical value, the faster the adjustment rate needed to destroy the temperature balance. The injection mold for automobile parts production is shown in Figure 2 .

[0055] The demand temperature value of the cavity at each moment and the demand temperature value of the core are obtained.

[0056] The absolute value of the difference between the demand temperature value of the cavity at each moment and the demand temperature value of the core is taken as the temperature difference theoretical value of the cavity and the core at each moment.

[0057] It is to be noted that: from the material supplier data, the temperature values required by the cavity and the core in each stage (such as the plastic melting stage, the injection stage, the pressure maintaining stage, etc.) during the mold injection process can be obtained, and thus the demand temperature value of the cavity and the demand temperature value of the core can be obtained according to the stage at each moment.

[0058] At the current moment, the absolute value of the difference between the temperature value of the cavity and the temperature value of the core is taken as the actual temperature difference of the cavity and the core.

[0059] At the current moment, the absolute value of the difference between the actual temperature difference of the cavity and the core and the temperature difference theoretical value of the cavity and the core is obtained the normalized value of the temperature adjustment rate requirement value.

[0060] It is to be noted that in the present embodiment, the normalized value of the temperature adjustment rate requirement value is taken as the normalized value of the temperature adjustment rate requirement value. the normalized value of the temperature adjustment rate requirement value. the normalized value of the temperature adjustment rate requirement value, wherein, is a linear normalization function for normalizing the data value to between 0 and 1. It is known that the adjustment of the temperature during the cooling process of the injection molded part is mainly the adjustment of the water temperature and the flow rate of the water cooling system, wherein the water temperature adjustment has a wider adjustment range, and the flow rate adjustment has a faster rate.

[0061] At the current time, the absolute value of the difference between the required temperature value of the cavity and the temperature value of the cavity is obtained, denoted as the cavity temperature deviation value, and the absolute value of the difference between the required temperature value of the core and the temperature value of the core is obtained, denoted as the core temperature deviation value.

[0062] At the current time, the product of the inverse value of the temperature adjustment rate requirement value (i.e. 1 minus the difference of the temperature adjustment rate requirement value) and the cavity temperature deviation value is obtained the normalized value of the temperature adjustment rate requirement value, denoted as the cavity water temperature adjustment probability, and the product of the inverse value of the temperature adjustment rate requirement value and the core temperature deviation value is obtained the normalized value of the temperature adjustment rate requirement value, denoted as the core water temperature adjustment probability.

[0063] It is to be noted that in the present embodiment, the normalized value of the temperature adjustment rate requirement value is taken as the normalized value of the temperature adjustment rate requirement value. and are taken as the normalized value of the temperature adjustment rate requirement value. and are taken as the normalized value of the temperature adjustment rate requirement value. When the cavity temperature deviation value or the core temperature deviation value is larger, the temperature needs to be adjusted more, and the temperature adjustment rate requirement value is larger, so the flow rate needs to be adjusted, because the flow rate adjustment has a faster rate, and vice versa, the temperature adjustment rate requirement value is smaller, so the water temperature needs to be adjusted, because the water temperature adjustment has a wider adjustment range.

[0064] The preset adjustment threshold is 0.5, which is taken as an example for description.

[0065] At the current time, if the cavity water temperature adjustment probability is greater than the preset adjustment threshold, the fuzzy control algorithm is used to adjust the temperature of the cooling liquid in the cavity cooling system, and if the cavity water temperature adjustment probability is less than or equal to the preset adjustment threshold, the fuzzy control algorithm is used to adjust the flow rate of the cooling liquid in the cavity cooling system, to complete the first temperature adjustment of the cavity.

[0066] If the core water temperature adjustment probability is greater than the preset adjustment threshold at the current time, the cooling liquid temperature in the core cooling system is regulated using a fuzzy control algorithm. If the core water temperature adjustment probability is less than or equal to the preset adjustment threshold, the cooling liquid flow rate in the core cooling system is regulated using a fuzzy control algorithm, and the first temperature adjustment of the core is completed.

[0067] It should be noted that the fuzzy control algorithm is a known technology, and its specific process is as follows: (1) First, fuzzification: read the cavity temperature deviation value (core temperature deviation value), and quantize it into different fuzzy levels through the membership function, wherein the membership function adopts the Gaussian membership function. (2) Then, regularization: according to expert knowledge, determine the fuzzy set and the corresponding output action group. (3) Then, reasoning: combine the fuzzy input with the rules in the rule base to perform reasoning calculation, and the result of reasoning is a fuzzy set, wherein the reasoning calculation process adopts the Sugeno reasoning method. (4) Finally, defuzzification: convert the fuzzy result into a specific control output, which is specifically realized by the maximum membership degree method.

[0068] Step S002: After the first temperature adjustment of the cavity and the core, the temperature values of each monitoring point in the cavity and the core at the next time of the current time, and the cooling liquid flow rate in the cavity and the core cooling system are obtained; the distance and temperature value difference between the monitoring points of the cavity and the core at the next time of the current time are determined to determine the local temperature difference consistency of the temperature zones of the cavity and the core.

[0069] It should be noted that further, the local temperature difference monitoring point needs to be determined, and the local temperature difference type needs to be judged. Based on the temperature deviation values of the cavity and the core, the temperature of the two temperature zones of the cavity and the core is adjusted respectively to meet the overall temperature requirement. However, due to the shape, thickness and cavity depth of the injection molded part, the cooling rate of different positions of the same injection molded part is different, thereby causing local temperature difference at different positions, i.e. the temperature of the local position of the cavity is different from that of other positions. At this time, the local temperature difference exists in the same temperature zone, which causes difficulty in temperature adjustment. The local temperature difference in the same temperature zone may have different sources, such as blockage of the water pipe of the cooling water line, which reduces the water flow and reduces the heat exchange, thereby causing local temperature difference. At this time, the local temperature difference cannot be directly adjusted, and the water cooling line needs to be repaired. The local temperature difference caused by the injection molded part itself can be adjusted by the water cooling system. At this time, the local temperature difference of the cavity and the core needs to be determined first. Before determining the local temperature difference type, the local temperature difference monitoring point in the abnormal monitoring point in the two temperature zones needs to be determined. Generally, the local temperature difference monitoring point first shows the temperature deviation, and the local temperature difference causes the temperature deviation of multiple adjacent monitoring points.

[0070] Preferably, in one embodiment of the present invention, the method for obtaining the consistency of local temperature difference between the cavity and the core includes:

[0071] After the first temperature adjustment of the cavity and core, the temperature value of each monitoring point in the cavity and core is obtained at the next moment, as well as the coolant flow rate in the cavity cooling system and the coolant flow rate in the core cooling system.

[0072] The preset temperature anomaly threshold is 0.7, and this will be used as an example for explanation.

[0073] At the next time step, obtain the average temperature value of all monitoring points within the cavity, denoted as the first average, and then obtain the absolute value of the difference between the temperature value of each monitoring point within the cavity and the first average. The normalized value is denoted as the temperature abnormality probability of each monitoring point. Monitoring points with a temperature abnormality probability greater than the preset temperature abnormality threshold are all recorded as abnormal monitoring points in the cavity at the next time step of the current time step. Monitoring points with a temperature abnormality probability less than or equal to the preset temperature abnormality threshold are all recorded as normal monitoring points in the cavity at the next time step of the current time step.

[0074] Based on the method of obtaining abnormal and normal monitoring points in the cavity at the next time step, obtain the abnormal and normal monitoring points in the core at the next time step.

[0075] It is important to note that maintaining consistent temperature across different locations within the cavity (core) of an injection mold is crucial, as it helps ensure the quality and dimensional accuracy of the molded part. Temperature consistency prevents uneven plastic flow, inconsistent cooling rates, and differences in shrinkage caused by localized overheating or undercooling, all of which can affect the final performance of the molded part. Therefore, the greater the difference between the temperature value at each monitoring point and the first average value, the more abnormal that monitoring point is.

[0076] The preset quantity threshold N is 3, and this will be used as an example for explanation.

[0077] At the next time step of the current time step, Dijkstra's algorithm is used to obtain the shortest path length between any two abnormal monitoring points in the cavity (i.e., the shortest path length from one abnormal monitoring point to another along the cavity surface). The sum of the shortest path lengths of each abnormal monitoring point in the cavity and all other abnormal monitoring points is obtained and recorded as the discreteness of each abnormal monitoring point. The N abnormal monitoring points with the smallest discreteness are recorded as the local temperature difference monitoring points in the cavity at the next time step of the current time step.

[0078] It should be noted that Dijkstra's algorithm is a well-known technique, and its specific method will not be described here. If the number of abnormal monitoring points in the cavity at the next time step is less than or equal to 3, then the abnormal monitoring points in the cavity at the next time step are directly recorded as the local temperature difference monitoring points in the cavity at the next time step.

[0079] Based on the method of obtaining the local temperature difference monitoring point in the cavity at the next moment of the current moment, obtain the local temperature difference monitoring point in the core at the next moment of the current moment.

[0080] It should be noted that localized temperature differences caused by the injection molded part itself arise from variations in the heat absorption and dissipation capabilities of different locations within the part. These localized temperature differences manifest simultaneously in both the cavity and the core, and their locations show a consistent relationship. Therefore, the type of localized temperature difference can be determined by the correspondence between the locations of these two temperature zones and the magnitude of the temperature difference. Furthermore, localized temperature differences caused by the injection molded part itself exhibit similar characteristics in both the core and cavity. Therefore, the higher the consistency in the locations of the monitoring points for localized temperature differences in the two temperature zones, the greater the likelihood that the issue is caused by the injection molded part itself.

[0081] At the next moment, from all the local temperature difference monitoring points in the cavity, obtain the local temperature difference monitoring point in the cavity that is closest to each local temperature difference monitoring point in the core, and denote it as the matching cavity monitoring point. Then, obtain the distance between each local temperature difference monitoring point in the core and the matching cavity monitoring point. The inversely proportional normalized value is denoted as positional consistency, and the absolute value of the difference between the abnormal probability of the temperature value at each local temperature difference monitoring point within the core and the matching cavity monitoring point is obtained. The inversely proportional normalized value is denoted as temperature difference consistency. The mean of positional consistency and temperature difference consistency is denoted as the local temperature difference consistency relationship of each local temperature difference monitoring point in the core. The mean of the local temperature difference consistency relationship of all local temperature difference monitoring points in the core is obtained and denoted as the local temperature difference consistency of the cavity and core.

[0082] It should be noted that the distance between each local temperature difference monitoring point inside the cavity and each local temperature difference monitoring point inside the core is obtained based on the Euclidean distance between the coordinates of the monitoring points (drilling position coordinates). and They represent and The inverse proportional normalized value.

[0083] Step S003: According to the consistency of the local temperature difference between the cavity and the core, combined with the temperature value difference between the monitoring points in the cavity and the core at the next moment and the cooling liquid flow rate in the cavity and core cooling system, the second temperature adjustment of the cavity and the core is respectively completed.

[0084] Preferably, in an embodiment of the present application, the method of completing the second temperature adjustment of the cavity and the core respectively comprises:

[0085] The preset classification threshold is 0.8, which is described as an example.

[0086] At the next moment of the current moment, when the consistency of the local temperature difference between the cavity and the core is greater than the preset classification threshold, it is determined that the local temperature difference of the injection mold at the next moment of the current moment is caused by the injection part itself, and when the consistency of the local temperature difference between the cavity and the core is less than or equal to the preset classification threshold, it is determined that the local temperature difference of the injection mold at the next moment of the current moment is caused by the water pipe fault.

[0087] It needs to be explained that: further, the adjustment strategy needs to be determined according to the type of local temperature difference. The above-mentioned local temperature difference is classified through the relationship between the two temperature zones of the core and the cavity, which is respectively caused by the injection part itself and the local temperature difference caused by the cooling water pipe fault. The local waterway appears blockage, scaling, leakage or joint loosening and other faults, which leads to poor water flow and sudden drop of heat dissipation efficiency. The root cause of this kind of local temperature difference is the physical failure of the waterway, not the heat balance demand, so it cannot be directly adjusted by water flow rate and water temperature. Therefore, the physical failure needs to be solved first, that is, the maintenance personnel needs to be reported for pipeline maintenance. For the local temperature difference caused by the injection part itself, the water temperature adjustment and the water flow rate adjustment are used for secondary temperature adjustment according to the actual temperature difference. At this time, the local temperature difference and the normal temperature difference exist in the same temperature zone, so the water temperature adjustment cannot be directly used to adjust the local temperature difference, because the water temperature adjustment changes the temperature of the cooling medium itself, thereby changing the heat exchange benchmark of the entire temperature zone. At this time, the water temperature adjustment based on the local temperature difference will lead to the change of the temperature of other normal areas in the entire circuit, thereby causing the temperature of the normal area to not meet the actual temperature demand. The adjustment of the water flow rate changes the heat exchange efficiency, and does not change the heat exchange benchmark, so the influence on the normal area is small. Therefore, for the local temperature difference caused by the injection part itself, the water flow rate adjustment is preferred. For the water flow rate adjustment, the main basis is the local temperature difference. Generally, the larger the local temperature difference, the greater the adjustment amount of the water flow rate. However, with the increase of the water flow rate, the adjustment efficiency of the water flow rate to the mold temperature decreases, and there is a limited flow rate for the adjustment of the mold temperature by the water flow rate. The closer the water flow rate is to the limited flow rate, the lower the adjustment efficiency.

[0088] The preset constant is 1, and the preset restricted flow rate is 3 meters per second, which is the restricted flow rate for water flow rate to regulate mold temperature. This will be used as an example for description.

[0089] At the next moment, when the local temperature difference between the cavity and core exceeds a preset classification threshold, the average temperature value of all abnormal monitoring points within the cavity (core) is obtained and recorded as the second average. The average temperature value of all normal monitoring points within the cavity (core) is obtained and recorded as the third average. The absolute value of the difference between the second and third averages is recorded as the magnitude of the local temperature difference within the cavity (core). Based on the principle of fuzzy control, the initial adjustment amount of the water flow rate is determined according to the magnitude of the local temperature difference within the cavity (core). The difference between the preset restricted flow rate and the coolant flow rate in the cavity (core) cooling system is obtained. When the difference When the difference is greater than 0, the difference will be... The inversely proportional normalized value is denoted as the degree to which the current water flow velocity approaches the restricted flow velocity. When the difference is... When the current water flow rate is less than or equal to 0, the preset constant is recorded as the degree to which the current water flow rate approaches the limited flow rate. The product of the degree to which the current water flow rate approaches the limited flow rate and the initial adjustment amount of the water flow rate is recorded as the correction amount of the water flow rate adjustment. The sum of the correction amount of the water flow rate adjustment and the initial adjustment amount of the water flow rate is recorded as the final adjustment amount of the water flow rate. Based on the final adjustment amount of the water flow rate, the coolant flow rate in the cavity (core) cooling system at the next next moment is adjusted to complete the second temperature adjustment of the cavity (core).

[0090] It should be noted that: with express The inverse proportional normalized value.

[0091] At the next moment, when the temperature difference between the cavity and the core is greater than the preset classification threshold, the second temperature adjustment of the core is completed in the same way as the second temperature adjustment of the cavity.

[0092] Based on the above operations, the secondary temperature regulation in mold temperature control is determined, that is, the mold temperature control is achieved by adjusting the flow rate of the cooling circuit water.

[0093] This invention is now complete.

[0094] To sum up, in the embodiment of the present application, according to the difference between the temperature value of the cavity and the core and the required temperature value at the current time, the first temperature adjustment of the cavity and the core is completed respectively, after the first temperature adjustment of the cavity and the core, the temperature value of each monitoring point in the cavity and the core at the next time of the current time and the flow rate of the cooling liquid in the cooling system of the cavity and the core are obtained, so as to determine the local temperature difference consistency of the temperature zone of the cavity and the core, and the second temperature adjustment of the cavity and the core is completed respectively. The present application can improve the precision of the temperature control of the injection mold, and is beneficial to the high-precision production of high-precision automobile parts.

[0095] The above merely describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. within the principles of the present application shall be included in the protection scope of the present application.

Claims

1. A temperature control method for injection mold of an automobile part production, characterized by, The method comprises the following steps: Obtain the temperature values of the mold cavity and the mold core at the current time and the required temperature values; determine the probability of water temperature adjustment of the mold cavity and the mold core according to the difference between the temperature values of the mold cavity and the mold core at the current time and the required temperature values; and complete the first temperature adjustment of the mold cavity and the mold core according to the size of the probability of water temperature adjustment of the mold cavity and the mold core. After the first temperature adjustment of the mold cavity and the mold core, obtain the temperature values of each monitoring point in the mold cavity and the mold core at the next time of the current time, and the flow rate of the cooling liquid in the cooling system of the mold cavity and the mold core; determine the local temperature difference consistency of the temperature zones of the mold cavity and the mold core according to the distance between the monitoring points and the temperature value difference between the mold cavity and the mold core at the next time of the current time. According to the local temperature difference consistency of the temperature zones of the mold cavity and the mold core, and in combination with the temperature value difference between the monitoring points in the mold cavity and the mold core at the next time of the current time and the flow rate of the cooling liquid in the cooling system of the mold cavity and the mold core, complete the second temperature adjustment of the mold cavity and the mold core. The specific steps for determining the probability of water temperature adjustment of the mold cavity and the mold core comprise the following steps: At the current time, obtain the absolute value of the difference between the required temperature values of the mold cavity and the mold core, denoted as the theoretical temperature difference of the mold cavity and the mold core; obtain the absolute value of the difference between the temperature values of the mold cavity and the mold core, denoted as the actual temperature difference of the mold cavity and the mold core; obtain the normalized value of the absolute value of the difference between the actual temperature difference of the mold cavity and the mold core and the theoretical temperature difference of the mold cavity and the mold core, denoted as the temperature adjustment rate requirement value; obtain the absolute value of the difference between the required temperature value and the temperature value of the mold cavity, denoted as the temperature deviation value of the mold cavity; obtain the absolute value of the difference between the required temperature value and the temperature value of the mold core, denoted as the temperature deviation value of the mold core; and obtain the normalized value of the product of the inverse value of the temperature adjustment rate requirement value and the temperature deviation value of the mold cavity, denoted as the mold cavity water temperature adjustment probability; and obtain the normalized value of the product of the inverse value of the temperature adjustment rate requirement value and the temperature deviation value of the mold core, denoted as the mold core water temperature adjustment probability.

2. A temperature control method for injection mold for automobile parts production according to claim 1, characterized in that, The specific steps for completing the first temperature adjustment of the mold cavity and the mold core according to the size of the probability of water temperature adjustment of the mold cavity and the mold core comprise the following steps: At the current time, if the mold cavity water temperature adjustment probability is greater than a preset adjustment threshold, a fuzzy control algorithm is used to regulate and control the temperature of the cooling liquid in the mold cavity cooling system, and if the mold cavity water temperature adjustment probability is less than or equal to the preset adjustment threshold, the fuzzy control algorithm is used to regulate and control the flow rate of the cooling liquid in the mold cavity cooling system, thereby completing the first temperature adjustment of the mold cavity. The first temperature adjustment of the mold core is completed according to the size of the mold core water temperature adjustment probability in the same manner as the first temperature adjustment of the mold cavity.

3. A temperature control method for injection mold for automobile parts production as claimed in claim 1 wherein, The specific steps for determining the local temperature difference consistency of the temperature zones of the mold cavity and the mold core comprise the following steps: At the next time of the current time, obtain the mean value of the temperature values of all monitoring points in the mold cavity, denoted as the first mean value, obtain the normalized value of the absolute value of the difference between the temperature value of each monitoring point in the mold cavity and the first mean value, denoted as the temperature value anomaly probability of each monitoring point, and monitoring points with a temperature value anomaly probability greater than a preset temperature anomaly threshold are all denoted as abnormal monitoring points. According to the distribution of the abnormal monitoring points in the cavity at the next time point of the current time point, the local temperature difference monitoring points in the cavity at the next time point of the current time point are screened from the abnormal monitoring points; According to the acquisition mode of the local temperature difference monitoring points in the cavity at the next time point of the current time point, the local temperature difference monitoring points in the core at the next time point of the current time point are acquired; According to the distance and the difference in temperature value abnormal probability of the local temperature difference monitoring points between the cavity and the core at the next time point of the current time point, the local temperature difference consistency of the temperature zones of the cavity and the core is determined.

4. A method for temperature control of injection mold for automobile parts production as claimed in claim 3 wherein, The specific steps of screening the local temperature difference monitoring points in the cavity at the next time point of the current time point from the abnormal monitoring points include the following: A preset number threshold N is set, and at the next time point of the current time point, the shortest path length of any two abnormal monitoring points in the cavity is acquired by using the Dijkstra algorithm, the sum value of the shortest path length of each abnormal monitoring point and all other abnormal monitoring points in the cavity is acquired, and the sum value is recorded as the discreteness of each abnormal monitoring point. The first N abnormal monitoring points with the smallest discreteness are recorded as the local temperature difference monitoring points in the cavity at the next time point of the current time point.

5. A temperature control method for injection mold for automobile parts production as claimed in claim 3 wherein, The specific steps of determining the local temperature difference consistency of the temperature zones of the cavity and the core according to the distance and the difference in temperature value abnormal probability of the local temperature difference monitoring points between the cavity and the core at the next time point of the current time point include the following: At the next time point of the current time point, from all the local temperature difference monitoring points in the cavity, the local temperature difference monitoring point in the cavity closest to each local temperature difference monitoring point in the core is acquired, which is recorded as a matching cavity monitoring point. The inverse proportional normalized value of the distance between each local temperature difference monitoring point in the core and the matching cavity monitoring point is acquired, which is recorded as the position consistency. The inverse proportional normalized value of the absolute value of the difference between the temperature value abnormal probability of each local temperature difference monitoring point in the core and the matching cavity monitoring point is acquired, which is recorded as the temperature difference consistency. The mean value of the position consistency and the temperature difference consistency is recorded as the local temperature difference consistency relationship of each local temperature difference monitoring point in the core. The mean value of the local temperature difference consistency relationships of all the local temperature difference monitoring points in the core is recorded as the local temperature difference consistency of the temperature zones of the cavity and the core.

6. A temperature control method for injection mold for automobile parts production as claimed in claim 3 wherein, The specific steps of completing the second temperature regulation of the cavity and the core according to the local temperature difference consistency of the temperature zones of the cavity and the core, combining the temperature value difference between the monitoring points in the cavity and the core at the next time point of the current time point, and the cooling liquid flow rate in the cooling system of the cavity and the core include the following: At the next time point of the current time point, for all the monitoring points in the cavity, the monitoring points with a temperature value abnormal probability less than or equal to a preset temperature abnormal threshold are recorded as normal monitoring points in the cavity at the next time point of the current time point. When the local temperature difference consistency of the temperature zones of the cavity and the core is greater than a preset classification threshold, the mean value of the temperature values of all the abnormal monitoring points in the cavity is recorded as a second mean value, the mean value of the temperature values of all the normal monitoring points in the cavity is recorded as a third mean value, and the absolute value of the difference between the second mean value and the third mean value is recorded as the local temperature difference size of the cavity. According to the local temperature difference of the cavity and the flow rate of the cooling liquid in the cavity cooling system, the second temperature adjustment of the cavity is completed; According to the mode of completing the second temperature adjustment of the cavity, the second temperature adjustment of the core is completed.

7. A method for temperature control of injection mold for automotive parts production as claimed in claim 6 wherein, The specific steps of completing the second temperature adjustment of the cavity according to the local temperature difference of the cavity and the flow rate of the cooling liquid in the cavity cooling system include the following: According to the principle of fuzzy control, the initial adjustment amount of the water flow rate is determined according to the local temperature difference of the cavity; Obtaining a difference between a preset limited flow rate and a flow rate of a coolant in a cooling system of a cavity When the difference is greater than 0, a reciprocal normalized value of the difference is recorded as a degree to which a current water flow rate approaches the limited flow rate When the difference is less than or equal to 0, a preset constant is recorded as the degree to which the current water flow rate approaches the limited flow rate When the difference is less than or equal to 0, a preset constant is recorded as the degree to which the current water flow rate approaches the limited flow rate When the difference is less than or equal to 0, a preset constant is recorded as the degree to which the current water flow rate approaches the limited flow rate The product of the degree to which the current water flow rate approaches the limited flow rate and the initial adjustment amount of the water flow rate is obtained, and is recorded as the correction amount of the water flow rate adjustment amount; The sum of the correction amount of the water flow rate adjustment amount and the initial adjustment amount of the water flow rate is recorded as the final adjustment amount of the water flow rate; According to the final adjustment amount of the water flow rate, the flow rate of the cooling liquid in the cavity cooling system at the next time is regulated at the current time, and the second temperature adjustment of the cavity is completed.

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